A computer tomography (CT) scanner includes an x-ray tube and a detector array. The x-ray tube is supported by a rotating gantry, which rotates about an examination region, thereby rotating the x-ray tube about the examination region. A detector array is located opposite the x-ray tube, across the examination region. The x-ray tube emits radiation that traverses the examination region (and a portion of a subject or object therein) and illuminates the detector array. The detector array detects radiation traversing the examination region and generates a signal indicative thereof. A reconstructor reconstructs the signal, generating three dimensional volumetric imaging data. A data processor can process the three dimensional volumetric imaging data and generate one or more images based thereon.
A conventional detector array has included a scintillator based detector array. A typical scintillator based detector array includes a scintillator array optically coupled to a photodiode array. By way of example, a conventional scintillator based detector array has included a gadolinium oxysulfide (GOS) based (e.g., Gd2O2S:Pr,Ce) scintillator array optically coupled to a silicon (Si) photodiode array. The radiation traversing the examination region illuminates the scintillator array, which absorbs the x-ray photons and, in response, emits optical photons, which are indicative of the absorbed x-ray photons. The photodiode array detects the optical photons and generates an electrical signal indicative of the detected optical photons. The reconstructor reconstructs this signal.
Gd2O2S:Pr,Ce based scintillator arrays have had a light yield or output of about 40,000 photons/MeV, with an afterglow suitable for CT applications. Generally, the light output corresponds to conversion efficiency, or the ability to convert absorbed x-ray photons into optical photons. Thus, there is an unresolved need for scintillator arrays with higher conversion efficiency and light output, with afterglow suitable for CT applications.